It is often desirable or convenient to deliver a medicament to a patient pulmonarily, using a dispensing device, such as an inhaler device (or simply, an “inhaler”). The inhaler device may be adapted to dispense a product, for example a medicament dose, from blisters within which a discrete dose of a medicament is stored. This is particularly the case for inhalers where the medicament is typically in a powdered form to be inhaled by a patient. Conventionally, blister-based unit dose inhalers use blister packs having only a single blister cavity which may be inserted, opened, and the medicament inhaled therefrom. However, such single dose inhalers may not be convenient for all patients since additional individual blisters must be carried with the inhaler device any time a patient will need to use multiple doses over a period of time. Additionally, unit dose inhalers require the patient to locate, manipulate, insert and remove the blister each time a medicament dose is desired.
Accordingly, multiple dose inhalers that use a blister strip have been developed. In such inhalers, the blister strip has a plurality of blisters thereon and the strip is moved (longitudinally or rotationally) so that blisters are sequentially presented to a dispensing position from which the medicament may be dispensed to the patient, such as during inhalation. The blisters are opened when they are positioned in the dispensing position, or as they are moved to the dispensing position.
Some medicaments or inhalers may use blisters that are comparatively large, and in such cases, arranging the blisters in blister strips may result in a device which is unacceptably large, inconveniently shaped, overly cumbersome to use, and/or contain too few doses of medicament to be widely accepted by patients.
In some inhaler devices, as blisters exit the inhaler device on the blister strip, the blisters must be removed and/or disposed of by cutting or tearing the blister strip, which is not considered a preferred patient use scenario. This is because the used blisters on the blister strip may hinder operation of the device, or may become a hindrance as they accumulate along with the device, or may disperse remaining medicament to locations exterior of the inhaler device, etc., any of which are not acceptable to patients.
In other inhaler devices, a single or dual take-up reel may be used to coil up used blisters in the interior of the inhaler device. However, these inhaler devices must be larger to account for the additional space necessary to house the used blisters.
In addition, since inhaler devices may be used by patients of all ages, strengths, and capabilities, it is useful that the inhaler device provide uniform and easy operation from the first blister to the last, including installation and removal of blister strips from the inhaler device. Some older and/or frailer patients may not have the requisite strength to operate an inhaler device in some operating conditions that a younger or stronger patient may be able to operate. However, each of these patients, irrespective of relative physical attributes (that is over a range of physical attributes) should be able to operate the inhaler device with equal ability regardless of the blister strip position in the inhaler device.